A selective differential low-noise amplifier includes a pair of transistors, each transistor of the pair being connected by its source to a current source and by its gate and/or its source to a differential voltage source, a coupling circuit between the gate of each transistor and the source of the other...http://www.google.de/patents/US7378907?utm_source=gb-gplus-sharePatent US7378907 - Selective differential low-noise amplifier
